1. Field of the Invention
This invention relates generally to adjustable shelving. More particularly the invention relates to an improved adjustable shelving system which permits ready shelf adjustment to any desired height as well as simplified assembly and disassembly of the system parts.
2. Description of the Prior Art
Adjustable shelving systems are well known. They are generally intended to be free standing without support of, for example, a wall and therefore require a certain combination of distinctive features and characteristics. Most particularly, these include a high degree of structural rigidity while retaining flexibility in the placement of shelves.
In the past, various shelving systems have been proposed which satisfactorily meet some of these criteria. A particular problem concerning the competing aspects of these criteria involves the manner in which the shelf and vertical support posts are attached. Several prior art systems utilize holes, screw fasteners and/or special tools to units these two elements. This approach has many drawbacks. Often the support poles are marred incident to relocation of shelving and, even if this problem is avoided, relocation of a given shelf within a system may become a difficult and a time consuming effort.
Certain alternative systems of the prior art which rely upon the use of an assembly intermediate the shelf and corner support posts are also known. Such systems are exemplified by those described in U.S. Pats. Nos. 3,424,111 and 3,523,503 of Louis Maslow. In these systems, interlocking bracket assembly are affixed around each corner support pole while encircling shelf retainers are placed over the poles and onto the assemblies to indirectly fix the shelf member in place on the corner support poles.
These latter systems represented a substantial advance in the art because of the simplicity with which they allow minor realignment or location of shelves. No tools or the like are required to perform this task. Notwithstanding this advance, however, they continue to exhibit drawbacks. Most particularly, a shelf must be removed upwardly from and over the entire length of the support poles because each corner shelf retainer encircles both the pole and intermediate bracket assembly. Consequently, where a lower shelf is to be removed from a multi-shelf system, each shelf above the one desired to be removed must also be disassembled to allow freedom of movement of the lower shelf.
Another serious drawback of this latter system is that it does not allow for complete flexibility in coupling shelving systems into a series composite. Thus, for example, where two separate shelving systems, each having corner support poles, are sought to be combined so as to result in a composite system composed of only three pairs of poles carrying two sets of shelves, the prior art does not allow the shelves of the two respective sets to be placed at the same height because their brackets cannot occupy the same position on the common pair of legs in the middle of the system. Moreover, because such a composite system results in having twice as many shelves on the intermediate common set of legs, it greatly complicates the difficulties of adjusting shelves after the system has been initially assembled in place. Twice as many shelves and assemblies may have to be disassembled and removed on the intermediate set of legs in order to allow adjustment or removal of a lower shelf from the system.